While carboxyl functional organosilicones are known, they are generally difficult and expensive to prepare and the commercial use thereof has therefore been limited. Heretofore, no convenient method for directly preparing polysiloxanes containing functional carboxylic acid groups is known and indirect routes for their preparation have generally been used, including hydrosilylation of an unsaturated ester followed by hydrolysis, or alternatively, by hydrolysis of nitrile-containing silicone fluids. However, polysiloxanes containing one or more functional groups such as amino groups are well known and readily available and have been used in a variety of commercial applications. Accordingly, the development of a method for readily and more directly preparing polysiloxanes containing one or more functional carboxyl groups would be desirable and it would be particularly advantageous if such method employed readily available materials such as amino functional polysiloxanes for not only preparing carboxyl functional polysiloxanes but a variety of organosilicone derivatives thereof as well, including silicone containing compositions which are readily soluble in a variety of solvents, preferably soluble in water such as silicone-containing phospholipid compositions and the like.
While, as indicated, polysiloxanes containing functional carboxylic acid groups and methods for preparing the same have heretofore been suggested, there is no disclosure or suggestion of the novel carboxyl functional silicone compositions described in copending application Ser. No. 174,660 filed Dec. 28, 1993 and application Ser. No. 298,565 filed Aug. 31, 1994 (now both abandoned) of which the present application is continuation in part or of the novel carboxyl functional silicone compositions of the present invention.